ASR9k will negotiate VC Type 4 with the 3825. By default the AC on the 3825 will pop tag 10 and the PW will add a fake one (could be the same though) to respect VC Type 4.

On the ASR9k, the AC will do nothing by default so you will end with a packet with a double tag. You need to apply the rewrite ingress pop 1 symmetric command on the ASR9k sub-interface so you will have the same behavior than the 3825.